@misc{OpreiSchreckingerKholiavkoetal., author = {Oprei, Anna and Schreckinger, Jos{\´e} and Kholiavko, Tatiana and Frossard, Aline and Mutz, Michael and Risse-Buhl, Ute}, title = {Functional and structural recovery of stream biofilms at the ha-bitat scale is based on the individual disturbance history}, series = {35. Jahrestagung der Deutschen Gesellschaft f{\"u}r Limnologie e.V. (DGL) und der Societas Internationalis Limnologiae (SIL) in M{\"u}nster, 23.-27. September 2019, Abstractband}, journal = {35. Jahrestagung der Deutschen Gesellschaft f{\"u}r Limnologie e.V. (DGL) und der Societas Internationalis Limnologiae (SIL) in M{\"u}nster, 23.-27. September 2019, Abstractband}, pages = {72 -- 73}, language = {en} } @misc{OpreiSchreckingerKholiavkoetal., author = {Oprei, Anna and Schreckinger, Jos{\´e} and Kholiavko, Tatiana and Mutz, Michael and Risse-Buhl, Ute}, title = {Variability of functional stream biofilm recovery at the habitat scale after disturbances from drying and sediment transport}, series = {11th Symposium for European Freshwater Sciences, June 30-July 5, 2019, Zagreb, Croatia, SEFS11 Abstract book}, journal = {11th Symposium for European Freshwater Sciences, June 30-July 5, 2019, Zagreb, Croatia, SEFS11 Abstract book}, pages = {338}, language = {en} } @misc{FischerKholiavkoSchaafetal., author = {Fischer, Thomas and Kholiavko, Tatiana and Schaaf, Wolfgang and Veste, Maik}, title = {Soil respiration responses of moss and lichen biocoenoses to moderate and severe rain events after summer drought in a temperate early-successional ecosystem}, series = {Ecohydrology}, volume = {16}, journal = {Ecohydrology}, number = {7}, issn = {1936-0592}, doi = {10.1002/eco.2578}, abstract = {It is commonly accepted that CO2 efflux increases with soil water content in aerated soils and that rewetting after periods of soil drying can result in respiration pulses. It has further been shown that soil pores may become water logged which can impede soil gas exchange. The present study aimed to quantify the carbon response of moss (Polytrichum piliferum) and lichen (Cladonia coniocraea) biocoenoses to different quantities of rain in an artificial catchment, which granted that the starting point of the development of both biocoenoses was the same. To address this aim, we conducted in situ soil moisture and soil respiration measurements, where soil respiration was hypothesised to emerge from a cryptogamic vegetation layer and from mineral soil beneath. We found that higher water-holding capacity of the moss layer and higher accumulation of organic matter in the upper mineral soil under mosses result in higher amounts of water stored near the surface. As a consequence, evaporation of water as well as pulses of CO2 efflux after moderate rain following a period of drought were higher in the moss biocoenosis, where the upper mineral soil was of key importance. In contrast, the lichen biocoenosis facilitated penetration of rainwater into the deep soil. Superimposing rewetting pulses, near-saturation of soil pores with water after severe rain resulted in gas exchange inhibition and diminished soil respiration until subsequent aeration in both biocoenoses}, language = {en} } @misc{OpreiSchreckingerKholiavkoetal., author = {Oprei, Anna and Schreckinger, Jos{\´e} and Kholiavko, Tatiana and Frossard, Aline and Mutz, Michael}, title = {Functional and structural recovery of stream biofilms at the habitat scale is based on the individual disturbance history}, series = {Ergebnisse der Jahrestagung 2019 in M{\"u}nster}, journal = {Ergebnisse der Jahrestagung 2019 in M{\"u}nster}, publisher = {Eigenverlag der DGL}, address = {Essen}, isbn = {978-3-9818302-4-8}, pages = {216}, language = {en} } @misc{OpreiSchreckingerKholiavkoetal., author = {Oprei, Anna and Schreckinger, Jos{\´e} and Kholiavko, Tatiana and Frossard, Aline and Mutz, Michael and Risse-Buhl, Ute}, title = {Long-term functional recovery and associated microbial community structure after sediment drying and bedform migration}, series = {Frontiers in Ecology and Evolution}, volume = {Vol. 11}, journal = {Frontiers in Ecology and Evolution}, issn = {2296-701X}, doi = {10.3389/fevo.2023.1112519}, abstract = {Climate change and erosion from agricultural areas cause increased drying periods and bedform migration of riverbeds, respectively, worldwide. Both sediment drying and bedform migration can independently stress the microbial community residing in the riverbed. Here, we investigated the microbial response after exposure to these stressors with a focus on long-term recovery. We conducted an in situ experiment to investigate the long-term (8 months) functional and structural recovery of benthic microbial communities from either sediment drying (episodic severe stressor) or bedform migration (frequent moderate stressor). Stressed sediment associated communities were rewetted (dried sediments) and immobilized (migrated sediments) and exposed in the River Spree (north-eastern Germany) to initiate the recovery process. We then evaluated the microbial function (community respiration, net community production and extracellular enzymatic activities) as well as the bacterial, fungal and diatom community structure (16S rRNA gene and ITS region metabarcoding, and microscopic diatom morphotype classification). We observed different recovery times for community respiration (less than 7 days) and gross primary production (more than 5 months), implying a shift toward net heterotrophy in the first few months after stress exposure. Similarly, we observed a strong autotrophic community response (particularly associated with the diatoms Navicula and Fragilaria), especially in migrated sediments. The bacterial and fungal community response to sediment drying was stronger than to bedform migration (particularly associated with the bacterium Flavobacterium and the fungi Alternaria sp. and Aureobasidium pullulans). Our results show that sediment drying and bedform migration had a significant impact on the microbial community function and structure, which persisted for several months after the stress. Due to the surprising long period of recovery, successive stress events combined with seasonal effects will likely hamper the ongoing recovery process with severe alterations to the microbial function and structure. These findings extend the concept of ecosystem resilience and stability on the dimensions of timescale and seasonal environmental variations. Legacy effects are expected to play a key role when facing future stress.}, language = {en} }